The invention generally relates to a parts sorter, and more particularly to an optical tablet and capsule counter for use in the pharmaceutical industry.
Optical counters for counting tablets and/or capsules have been known in the pharmaceutical industry for some time. Such counters take various forms. It is generally the common goal of such counters to reduce a pile of tablets or capsules to a single one-dimensional row so that they may be counted as they move past an optical sensor. Some of the various systems for accomplishing the same include rotational and linear vibrators, rotating discs, air jets, gravity feeds, moving belts, etc. Each system has its benefits and drawbacks.
Among the difficulties encountered by optical tablet or capsule counter systems are the requirements of: having a high throughput and accuracy; allowing different size tablets and capsules to be accommodated without undergoing extensive or difficult adjustments in the machine; providing an automatic feed and collection of tablets and capsules in excess of a selected or desired quantity; and providing for the tablets and capsules to be deposited directly into a final container, all with the goal of providing a relatively small sized, reliable counter. In the past, in order to obtain some of the goals, various other goals have been ignored or highly compromised. Typically, high count rate and highly accurate machines have been large in size, while smaller machines have been less accurate or have suffered from low throughput. Moreover, the art has not provided any small, high count rate, accurate machines capable of accommodating various tablet and capsule sizes without difficult machine adjustments.
Among the various sorters and counters known are those found in the following patents which are representative of the prior art:
______________________________________ U.S. Pat. No. Inventor U.K. Patent No. Inventor ______________________________________ 3,095,960 Luginbuhl 565,275 Thomson 3,355,003 Wayne et al. 584,227 Hurst 3,444,980 Wiseman 617,693 Bayes 3,730,386 Monsees 671,821 Daniels 3,767,027 Pund et al. 761,553 Gregory 4,029,195 Hartness et al. 838,230 Packman 4,129,207 Cupp 931,124 Nobel-Bozel 1,013,533 Korber 1,079,174 Fox et al. 1,093,800 Cutler 1,290,961 AMF, Inc. 1,318,988 Blanchaud et al. ______________________________________
Of particular interest among the listed patents are the U.S. Pat. Nos. 4,129,207, to Cupp and 3,730,386 to Monsees. The Cupp patent discloses a sorter for hamburger buns which are forced to assume an hexagonal close pack arrangement before being divided into one-dimensional streams. The Cupp patent assumes that the buns are in a two-dimensional arrangement (i.e. unstacked) when they reach a diverging descending chute section, and no means for eliminating stacked buns is provided. Moreover, in the Cupp patent, means for counting the buns coming off of the chute in a parallel manner is not provided, nor are means for directing the parallel buns to single locations in desired numbers.
The patent to Monsees U.S. Pat. No. 3,730,386 discloses a counting machine for egg rolls. Successive conveyors at higher rates are used to separate the egg rolls into a single one-dimensional stream. The single stream is accommodated in a single V-shaped channel which has low enough sides to permit any egg rolls which may be atop other egg rolls to fall over the side of the channel. The Monsees patent suffers from low throughput, as only a single channel is provided.